Review Reports

Round 1

Reviewer 1 Report

In article authors focus on the production level implementation of routing in hybrid SDN and its performance comparison with legacy network to measure the viability of transition towards pure SDN by implementing ONOS/SDN-IP.

Presented problem and obtained results are interesting. However, the article has some weaknesses. 

Descriptions of some figures should be extended - i.e. presenting some of the results as more detailed data (not just graphs) would make the results easier to read.

Discussion of the results should be extended too.

Author Response

Respected Reviewer,

We are highly thankful for your constructive comments so that we are able to massively refine our article accordingly to meet the standards.

All the changes made in the revised manuscript are highlighted in color BLUE. The response of reviewer's comments are attached as separate PDF file.

We thank you for your time and careful reviews.

 

Regards

Author(s) 

Author Response File: Author Response.pdf

Reviewer 2 Report

The article's related work section lists a set of studies in SDN but does not present any work that has done a performance evaluation of SDN in ISP networks, like proposed in this work, highlighting strengths and differences between their and the present work.

The experimental results are difficult to reproduce. Publishing the code on GitHub would help the community to verify the author's claims. Having an analysis on the queue lengths on the network devices would help understanding the impact of the SDN on network congestion. The trends of the curves in Figures 9-11 are highly irregular, but no in-depth explanation was provided for that behavior. Furthermore, the plots could report confidence intervals to strengthen the article's statistical relevance.

 

 

 

 

 

 

Author Response

Respected Reviewer,

We are highly thankful for your constructive comments so that we are able to massively refine our article accordingly to meet the standards.

All the changes made in the revised manuscript are highlighted in color BLUE. The response of reviewer's comments are attached as separate PDF file.

We thank you for your time and careful reviews.

 

Regards

Author(s) 

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors in this manuscript propose an interesting question to be investigated around the integration between the Legacy IPv4 networks and the SDN networks for a migration of the functional environment of SDN that addresses issues as minimizing expenditures of running network infrastructure.

 

The author's findings show that the performances of the SDN network are much better than its legacy counterpart taking into account the bandwidth capacity, the packet transmission rate, and the round trip time, each of them collected and compare with simulations.

They show that SDN-IP provides better bandwidth and latency compared to legacy routing.  Moreover, they evaluate a hybrid SDN implementation and routing performance evaluation by comparing the legacy routing and SDN routing with their interoperability through an experimental analysis using open network operating system (ONOS)/SDN-IP.

 

 

I have some minor comments to be addressed, as follows:

 

1. What are the hardware and software setups for the experimentation?
2. How do the findings compare with state-of-the-art benchmark methods?
3. What is the implication in a future 6G scenario? 
4. The authors need to check very well the English language. There are too many typos in the text. Thus, please revisit the manuscript to correct typos and several grammatical errors. 
5. Summarize the research contributions of the paper, preferably in point-form.

Author Response

Respected Reviewer,

We are highly thankful for your constructive comments so that we are able to massively refine our article accordingly to meet the standards.

All the changes made in the revised manuscript are highlighted in color BLUE. The response of reviewer's comments are attached as separate PDF file.

We thank you for your time and careful reviews.

 

Regards

Author(s) 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Some issues remain compared to the previous version. The proposed solution should be compared with at least another non-naive SDN routing approach, and the results should be presented to support the main thesis of the article (it is hard to follow the logical consequence of the presented results and where they want to lead the reader). Plots with RTT variance should not present such variability and should be considered at steady state, or, in alternative, average several simulation runs to obtain statistically relevant claims.

Author Response

Respected reviewer,

We are thankful for your time and careful review. The response of comments are attached in the PDF file. 

 

Regards

Author(s)

Author Response File: Author Response.pdf